Locating regional lung dysfunction by analysis of ventilation distributions

A technique has been investigated for locating lung lesions noninvasively by examining ventilation distributions. Data from several nitrogen washout procedures performed with the subject at different body positions are used to compute ventilation distribution curves, one curve for each body position. Distribution of ventilation changes with body position due to hydrostatic pressure changes. Data are graphed with seatback angles vs. ventilation vs. ventilation distribution. The location of a regional lung dysfunction is reflected in changes in the pattern formed by the three-dimensional plot of ventilation distributions. These changes are apparent upon comparison to curves representing normal lungs. The location of the dysfunction is determined by statistical analysis of specific curve characteristics